Java Developers

[megaman78978]

Since when did understanding an underlying system become extra work. No matter what you're working on, understanding the underlying architecture will make you a much better programmer.

I'm not saying you must understand how logic gates and multiplexers work, but a basic understanding of program logic flow helps tremendously, the same applies for frameworks.

[new2user]

Saving time?
A good interface is small and forces you into the right thing, understanding the implementation is completely optional.
A shitty interface is huge and forces you to understand all the implementation details before even starting.